In a compressor that uses a permanent magnet embedded electric motor as a drive source, a stator core of an electric motor is often fixed to an inner circumferential section of a cylindrical frame by using a shrink-fit or press-fit. The stator core of a conventional electric motor as described in Patent Literature 1 has a back yoke and a plurality of magnetic pole teeth extending from the back yoke in a direction toward the center of the electric motor. The stator core is fixed inside the outer circumferential section of the back yoke by the shrink-fit, in a state in which the outer circumferential section of the back yoke corresponding to each of the magnetic pole teeth is not in contact with the inner circumferential section of the frame and in a state in which the outer circumferential section of the back yoke other than the position corresponding to the magnetic pole teeth is in contact with the inner circumferential section of the frame. Because a part of the outer circumferential section of the back yoke is in a state of not being in contact with the inner circumferential section of the frame in this way, a gap between the stator core and the rotor is prevented from becoming uneven due to the deformation of the stator core. In the conventional technique described in Patent Literature 2, a plurality of stress relaxation slits are formed on an outer circumferential section of a split yoke portion corresponding to a split stator core, and when a stress-receiving section provided in each of the stress relaxation slits is deformed, the compression stress occurring in a magnetic flux region in the split yoke is reduced, thereby improving the iron loss characteristics in the split stator cores.